Kate Middleton may not have planned a lavish celebration for her thirtieth birthday on Jan. 9, but the dress she wore on the eve of her birthday said it all.

Catherine, the Duchess of Cambridge, had a stunning start to her first birthday eve in the royal family. She attended the UK premiere of the film War Horse at the Odeon Leicester Square cinema in London on Jan. 8 in her usual striking style.

Kate donned a floor-length, full-sleeved black lace dress that added to her elegance and style statement on the red carpet.

Accompanied by her husband Prince William, the Duke of Cambridge, Kate teamed up her attire with a velvet clutch and accessorized with her engagement ring and a bracelet.

The UK premiere of the Steven Spielberg film was an aid of The Foundation of Prince William and Prince Harry. Scroll down to view the pictures of the royal patrons at the film’s premiere.

Kate Dazzles on the eve of her birthday
Kate, the Duchess of Cambridge, attended her first royal film premiere on the eve of her 30th birthday, when Steven Spielberg's War Horse was shown at the Odeon in Leicester Square Reuters
Kate Dazzles on her Birthdays Eve
Britain's Catherine, Duchess of Cambridge, arrives at the UK premiere of the film 'War Horse' in London Jan. 8, 2012. REUTERS
Kate Dazzles on her Birthdays Eve
Britain's Prince William and Catherine at the UK premiere of 'War Horse' at the Odeon Leicester Square cinema in London Jan. 8, 2012. REUTERS
Kate Dazzles on her Birthdays Eve
Britain's Prince William (centre L) and Catherine attend the UK premiere of War Horse on the eve of her thirtieth birthday at the Odeon Leicester Square cinema in London Jan. 8, 2012. REUTERS
Kate Dazzles on her Birthday039s Eve
Catherine, Britain's Duchess of Cambridge, and Britain's Prince William leave the UK premiere of 'War Horse', London, Jan. 8, 2012. REUTERS/Paul Hackett
Kate Dazzles on her Birthdays Eve
Britain's Prince William (L) arrives with Catherine, Duchess of Cambridge, to the UK premiere of the film 'War Horse' in London Jan. 8, 2012. REUTERS/Paul Hackett
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